First unzip it into your interface\addons directory. It should be in its own folder called SCT. Now just run WoW and once logged in, type /sct to get the options screen.

SCT_EVENT_CONFIG.LUA is used to setup custom message events. Please open up the file (notepad, etc...) and read the opening section to understand how to use it all.PLEASE NOTE - THIS IS THE MOST IMPORTANT FILE IN SCT. IF YOU DON'T READ IT AND USE IT, THEN YOU ARE MISSING OUT ON A TON OF WHAT SCT HAS TO OFFER IN CUSTOMIZATION